Levels of CD68 positive cells in WKYRs and SHRs after Et-1 injection. Brain slices from WKYRs (n = 4) and SHRs (n = 4) treated with 200 pmol Et-1 were stained with anti-CD68 and the density of CD68+ cells was assessed in three fixed regions of the striatum and one region in the cortex (see Figure 1B) . Representative micrographs from two fixed regions in the striatum (A and D, upper left region; B and E upper right region) and one region in the cortex (C and F, in the center of the indicated region) are shown for WKYRs (A-C) and SHRs (D-F). Scale bar = 50 μm. Densities of CD68+ cells in the striatum (G) and cortex (H) are provided for both strains. The expression of CD68 remained low in the sham operated groups (n = 3 to 4 for the WKYR’s and n = 4 for the SHRs). *Significant difference between WKYRs and SHRs. $ Significant difference between sham and Et-1 treated animals. ns: no significant difference between WKYRs and SHRs.